Gypsum Board with Multiple Tapered Edges

ABSTRACT

A gypsum board with multiple tapered edges has a flat, rectangular main flat body with four tapered edges. The main flat body is a gypsum core sandwiched between two paper sheets. The main flat body may be of any appropriate size, including 4 feet by 4 feet or other sizes. In a method for manufacturing the gypsum board with multiple tapered edges, a quantity of gypsum slurry is fed between two continuous paper sheets with a conveyor system to make a continuous gypsum sheet and longitudinal edges of the continuous gypsum sheet are tapered. The gypsum slurry is partially dried, and then the continuous gypsum sheet is transversely compressed between an upper bracket and a lower bracket to form a transverse tapered impression. The continuous gypsum sheet is cut at the tapered impression, and the transverse tapered edges are enclosed with finishing paper.

The current application claims a priority to the U.S. Provisional Patent application Ser. No. 61/638,693 filed on Apr. 26, 2012.

FIELD OF THE INVENTION

The present invention relates generally to the construction of houses and other buildings. More particularly, the present invention relates to a gypsum board (drywall sheet) with all edges being tapered and a method for fabrication of said gypsum board with multiple tapered edges.

BACKGROUND OF THE INVENTION

A home is a place of residence or refuge. When it refers to a building, it is usually a place in which an individual or a family can live and store personal property. A home is generally a place to provide safety, and is used as a center from which people base their daily activities. Most modern-day households contain living spaces, sanitary facilities, a means of preparing food and sleeping quarters.

Home construction is the process of building a home using many varied materials. Inhabited areas need homes for the inhabitants to live in and new residential developments are constantly being built. Home construction techniques have evolved from simple pre-historic shelters to the vast multitude of living accommodations available today. Different levels of wealth and power have warranted various sizes, layouts, luxuries, and even defenses in a home. Home construction projects are not limited to building a new home, and may often take the form of renovations to beautify or update a building, or repairing damage from accidents, weather or wear.

Drywall, also known as gypsum board, plasterboard, or wallboard, is a panel made of gypsum plaster pressed between two thick sheets of paper and has become the building material of choice to provide the finishing on most interior walls and ceilings in most modern buildings. Drywall is useful in construction for characteristics including resistance to fire, dimensional stability, low cost, and easy workability. Drywall construction became prevalent in the early 1950's as a cheaper, quicker and easier to use alternative to traditional lath and plaster construction. Many construction projects utilize drywall to make interior walls and ceilings. In most homes, nearly every wall and ceiling is made of drywall covered by at least one coat of primer to seal the plaster and top paper sheet before at least one coat of paint is applied. Drywall generally comes in flat, rectangular sheets in various sizes (4 feet by 8 feet, 4 feet by 9 feet, 4 feet by 10 feet, 4feet by 12 feet & soon the new sheet measuring 4 feet by 4 feet), and in various thicknesses, typically including ¼ inch, ⅜ inch, ½ inch, and ⅝ inch. Other types of gypsum board exist, such as “Green board”, which has the same gypsum core as standard drywall but with a thicker water-resistant paper covering for applications where higher humidity is a consideration, and “Fire Code” drywall which is ⅝ inches thick and fire resistant.

One significant characteristic of drywall is its weight. The average ½ inch drywall sheet weighs 1.8 pounds per square foot, meaning that a typical 4 foot by 8 foot drywall sheet weighs 57.6 pounds each. This is not a trivial amount of weight for most people, and the fact that the weight is distributed over a large area makes drywall sheets unwieldy and difficult to handle. The introduction of the new drywall sheet of the present invention measuring only 4 feet by 4 feet with all edges tapered and weighing less than 30 pounds each will make drywall installation much easier. Installation of drywall, especially on ceilings or elevated areas, often requires two people working together, but some projects lack the budget necessary to hire an extra person. In a situation where a single person attempts to install drywall alone, but is incapable of managing the full drywall sheet, be it 4 feet by 8 feet or even 4 feet by 12 feet, single handedly may halve the drywall sheet and install it in two separate sections. Merely cutting, for instance, a 4 by 8 sheet into two mini sheets measuring 4 feet by 4 feet and installing these un-tapered mini sheets in the traditional manner (vertically) creates a “butt” seam at the 4 foot height and said seam is impossible to finish like a tapered edged seam.

In the installation process, after the drywall sheet is affixed to wall studs, the seams between sheets must be finished by being filled and covered with plaster (joint compound). Typical drywall sheets are tapered at the side edges, producing a recess for joint compound (plaster) to fill when tapered edged sheets are laid (affixed or secured) next to each other. When cut sections of drywall are laid with the cut ends abutted together, there is no recess into which the joint compound (plaster) can be put, causing a ridge at the joint, or a “butt” seam. The addition of tapers to all edges will do much to solve this problem by providing a recess at any joint between drywall sheets.

The value inherent to having a gypsum board (drywall sheet) with all edges being tapered has been known and appreciated for many years. The addition of tapers to all edges will provide a recess to accommodate the patching tape and plaster (joint compound) needed to facilitate the finishing of any and all joints between all installed drywall sheets regardless of size.

Most, if not all of the prior art in connection with the aforementioned invention offer a method and apparatus to apply additional tapers to drywall after market. So far none of these methods and apparatus has succeeded in fulfilling their aspirations. This is not the method proposed herein. To date there is still no commercially viable method of continuous production of four tapered edge drywall in spite of the dire need for such a method throughout the building industry.

With the introduction of smaller tapered drywall sheets, the average do-it-yourselfer will be more confident in tackling drywall installations on their own. With the ability to completely taper a drywall sheet the introduction of a drywall sheet smaller than 4 feet by 8 feet becomes feasible as the elimination of all “butt” seams becomes a reality. In the preferred embodiment of the present invention a drywall sheet measuring 4 feet by 4 feet with all edges tapered can now be manufactured as it will no longer be subject to “butt” seam problems. Such a drywall sheet will be more manageable for an individual installer. (Easier to transport and install)

It is therefore an object of the present invention to provide a method and apparatus for a new drywall sheet with all edges tapered and measuring 4 feet by 4 feet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of the apparatus of the present invention with all edges tapered.

FIG. 2 is a top perspective view of the apparatus of the present invention with three tapered edges and one untapered edge demonstrating the differences between the two.

FIG. 3 is an enlarged side view (not to scale) of the apparatus of the present invention.

FIG. 4 is an enlarged side view (not to scale) of the cross section of a tapered edge from the apparatus of the present invention.

FIG. 5 is a top view of five possible sizes of the present invention.

FIG. 6 is a diagram of the continuous gypsum sheet on the conveyor system prior to making the transverse tapered impression.

FIG. 7 is a diagram of the upper and lower brackets that create the transverse tapered impressions in the continuous gypsum sheet.

FIG. 8 is a diagram showing cut locations at the transverse tapered impressions to create new gypsum sheet sections with transverse tapered edges.

FIG. 9 is a diagram showing the new gypsum sheet section once the cuts have been made along the cut lines.

FIG. 10 is a diagram showing the plastering of two drywall sheets with non-tapered edges resulting in a visible raised seam.

FIG. 11 is a diagram showing the plastering of two drywall sheets with tapered edges resulting in a flush seam.

FIG. 12A is a stepwise flow diagram for the overall method of the present invention.

FIG. 12B is a continuation of the stepwise flow diagram for the overall method of the present invention.

FIG. 13 is a stepwise flow diagram for the method of adding transverse tapers during manufacture according to the preferred embodiment of the present invention.

DETAIL DESCRIPTIONS OF THE INVENTION

All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention.

The present invention is a gypsum board with multiple tapered edges and a method for manufacturing said gypsum board with multiple tapered edges. Said method and apparatus will entail impressing a triangular tapering protrusion 71 into a continuous gypsum sheet 9 (slurry filled) to form a tapered impression 5. The continuous gypsum sheet 9 (slurry filled) will be cut into sections along cut lines 14 producing drywall sheets with multiple tapered edges, and in various lengths.

The present invention solves the problem of “butt” seams created by installing two drywall sheets with abutting untapered edges 25. As seen in FIG. 10, when two untapered drywall sheets 40 are abutted, there is no recess into which a plaster joint compound 30 can be deposited, resulting in a visible raised seam 51. FIG. 11 shows the installation of two drywall sheets with tapered edges 41 and demonstrates the creation of a recess between installed sheets into which plaster-joint compound 30 can be deposited, creating a tapered joint 52 that is a flat seam with no raised mound.

Referring to FIGS. 1-5, the gypsum board with multiple tapered edges comprises a main flat body 1 and a plurality of edges 2. The main flat body 1 takes up the majority of the space the present invention occupies, having flat, rectangular geometry similar to existing gypsum boards. As can be seen in FIG. 4, the main flat body 1 comprises a first paper sheet 11, a second paper sheet 12, and a gypsum core 13. As seen in FIGS. 1-2, the plurality of edges 2 is positioned on the main flat body 1 and is perimetrically connected around the main flat body 1. In the preferred embodiment of the present invention, the main flat body 1 has a thickness such as, but not limited to, ¼ inch, ⅜ inch, ½ inch, or ⅝ inch.

The gypsum core 13 is made from a slurry of gypsum and various other ingredients such as, but not limited to, plasticizer, foaming agent, finely ground gypsum crystal, Ethylenediaminetetraacetic acid, starch or another chelate, and various additives that may increase mildew resistance and fire resistance, or other ingredients. A wet gypsum slurry is sandwiched between the first paper sheet 11 and the second paper sheet 12, which, when dried, becomes rigid and strong enough for use as a building material, forming the gypsum core 13 that is positioned between the first paper sheet 11 and the second paper sheet 12. In the preferred embodiment of the present invention, the main flat body 1 has dimensions of 4 feet by 4 feet, but is not limited to said dimensions.

Referring to FIGS. 1 and 2, in the preferred embodiment of the present invention, the plurality of edges 2 comprises a first tapered edge 21, a second tapered edge 22, a third tapered edge 23, and a fourth tapered edge 24. The second tapered edge 22 and the fourth tapered edge 24 are unique aspects of the present invention, as current gypsum board only has two tapered edges, which are the first tapered edge 21 and the third tapered edge 23. For reference, a first side 3 is defined as being coincident with the first paper sheet 11, and a second side 4 is defined as being opposite the first side 3 and adjacent to the second paper sheet 12. As can be seen in FIG. 4, for each of the plurality of edges 2 that is tapered, the thickness of the gypsum board decreases moving in a direction from the center of the main flat body 1 to the respective extremity of the edge. In FIG. 2, an untapered edge 25 is shown to demonstrate the difference between a tapered edge and an untapered edge.

Referring to FIGS. 3 and 4, the sloped portion of each of the plurality of edges 2 that is tapered is such that only the first side 3 is tapered, while the second side 4 is flat and untapered. As can be seen in FIG. 4, a cross section of each of the plurality of edges 2 that is tapered resembles a right trapezoid, with the right angles of the right trapezoid adjacent to the second paper sheet 12 and the thickness of the gypsum board decreasing toward the respective extremity. In the preferred embodiment of the present invention, each tapered edge is tapered by an amount that is much smaller than the thickness of the main flat body 1, preferably ⅛ inch. For example, if the main flat body 1 is ⅝ inches thick, a taper reduces the thickness at the respective extremity to ½ inch, resulting in a difference in thickness of ⅛ inch. The horizontal component of the sloped portion from the respective extremity of an edge inward to the maximum thickness of the main flat body 1 is approximately 2 inches, though the length of the taper may be other appropriate or desired dimensions.

As can be seen in FIGS. 1 and 2, the plurality of edges 2 is arranged in a rectangle around the main flat body 1. The first tapered edge 21 and the third tapered edge 23 are oriented parallel to each other and are positioned opposite from each other across the main flat body 1. The second tapered edge 22 and the fourth tapered edge 24 are oriented parallel to each other and are positioned opposite from each other across the main flat body 1. The first tapered edge 21 is oriented perpendicular to the second tapered edge 22. The second tapered edge 22 and the fourth tapered edge 24 are positioned adjacent to the first tapered edge 21 and the third tapered edge 23, so that first tapered edge 21, the second tapered edge 22, the third tapered edge 23 and the fourth tapered edge 24 form a rectangular perimeter around the main flat body 1. As can be seen in FIG. 2, in an alternate embodiment of the present invention, the fourth tapered edge 24 is replaced with an untapered edge 25 for a gypsum board with three tapered edges.

Referring to FIG. 5, in alternate embodiments of the present invention, the main flat body 1 has other dimensions, including, but not limited to, 4 feet by 8 feet 42, 4 feet by 9 feet 43, 4 feet by 10 feet 44, 4 feet by 12 feet 45, or 4 feet by 4 feet 46.

The method of the present invention is a method for manufacturing the drywall sheet with multiple tapered edges. It should be understood that the method of the present invention does not contemplate changing the entire process for manufacturing gypsum board, but merely adding steps to said manufacturing process. The method for manufacturing the gypsum board with multiple tapered edges is as follows.

As illustrated in FIGS. 6, 7, 8, and 9 and described in FIGS. 12A and 12B, a conveyor system 10 is provided 101, a quantity of gypsum slurry is provided 102, and an upper paper sheet 17 and a lower paper sheet 16 are provided 103. The first paper sheet 11 of the gypsum board with multiple tapered edges is a sectional piece of the lower paper sheet 16, and the second paper sheet 12 of the gypsum board with multiple tapered edges is a sectional piece of the upper paper sheet 17.

An upper bracket 6 and a lower bracket 7 are also provided 104, and a dividing blade 8 is provided 105. The lower bracket 7 comprises a triangular tapering protrusion 71 and a piercing protrusion 72. Initially, the upper paper sheet 17 and the lower paper sheet 16 are continuous, being fed off respective rolls of paper. The conveyor system 10 may be any appropriate mechanical system for moving the various stages of the gypsum board along a production line. In the preferred embodiment of the present invention, one section of the conveyor system 10 comprises a small transverse gap 18 for raising the lower bracket 7 in order to form the transverse tapered impression 5.

As described in FIG. 12A, a continuous gypsum sheet 9 is formed by continuously feeding the quantity of gypsum slurry between the upper paper sheet 17 and the lower paper sheet 16 as the upper paper sheet 17 and the lower paper sheet 16 move along the conveyor system 10 toward a tapering location 106. A length of the continuous gypsum sheet 9 is defined by movement along the conveyor system 10, and longitudinal edges of the continuous gypsum sheet 9 are parallel to the movement of the conveyor system 10.

After the quantity of gypsum slurry is fed between the upper paper sheet 17 and the lower paper sheet 16, the longitudinal edges of the continuous gypsum sheet 9 are tapered using previously known methods of gypsum board manufacturing, or by using another appropriate method 107.

A period of time is allowed to pass for the gypsum slurry held within the upper paper sheet 17 and the lower paper sheet 16 to partially dry 108. The gypsum slurry is allowed to dry to a point where the gypsum slurry holds its form as a moldable solid but can still be shaped by applying a compressive force. At this point, the continuous gypsum sheet 9 is moved to the tapering location to receive a transverse tapered impression 5 prior to being separated into various sheet lengths.

Referring to FIGS. 7, 12B and 13, the transverse tapered impression 5 is formed by transversely compressing the continuous gypsum sheet 9 between the upper bracket 6 and the lower bracket 7 at a specified location along the length of the continuous gypsum sheet 109. The transverse tapered impression 5 is made adjacent to the lower paper sheet 16. To form the transverse tapered impression 5, the lower bracket 7 is raised through the transverse gap 18 enough to allow the triangular tapering protrusion 71 with the piercing protrusion 72 attached to form the tapered impression 5 in the continuous gypsum sheet 9. The transverse gap 18 is preferably a gap between rollers 15 of the conveyor system 1091. The piercing protrusion 72 of the lower bracket 7 pierces through the lower paper sheet 16 in order to release tension on the lower paper sheet 16 and allow the now-pierced portions of the lower paper sheet 16 to conform to the triangular tapering protrusion 71. The triangular tapering protrusion 71 compresses the partially dried gypsum slurry adjacent to the lower paper sheet 16 to finish the tapering process 1092.

As seen in FIG. 7 and described in FIG. 13, the upper bracket 6 presses against the continuous gypsum sheet 9 opposite the lower bracket 6 for stability during the transverse tapering process 1093. The upper bracket 6 presses against the upper paper sheet 17 with a flat surface that spreads out the compressive force adjacent to the upper paper sheet 17. The upper bracket 6 allows the force transmitted by the lower bracket 7 to compress the gypsum slurry adjacent to the lower paper sheet 16 into the transverse tapered impression 5. A transverse portion of the gypsum slurry is compressed adjacent to the lower paper sheet 16 into an isosceles triangular shape so that equal sides of the isosceles triangle converge in a direction from the lower paper sheet toward the upper paper sheet 1094.

As described in FIG. 12B and illustrated in FIGS. 6-9, the continuous gypsum sheet 9 is divided into new gypsum sheet sections 48 after forming the transverse tapered impression 5. By centrally cutting the transverse tapered impression 5 with the dividing blade 8, the new gypsum sheet section 48 is produced 110. In FIGS. 8 and 9, the vertical dotted lines represent cut lines 14. The cut lines 14 are located at the apex of the tapered impression 5. FIG. 9 illustrates the separation of the continuous gypsum sheet 9 into individual new gypsum sheet sections 48 at the appropriate cut lines 14. When the continuous gypsum sheet 9 is cut, the longitudinal edges of the continuous gypsum sheet become the first tapered edge 21 and the third tapered edge 23 of two consecutive new gypsum sheet sections 48.

The new gypsum sheet section 48 now has longitudinal tapered edges and at least one transverse tapered edge. As described in FIG. 12B, to finish forming the new gypsum sheet section 48, the new transverse tapered edges (the first tapered edge 21 and the third tapered edge 23) are enclosed with a finishing paper 111.

A period of time is then specified to wait until the finished new gypsum sheet section 48 is completely dry 112. Preferably, the finished new gypsum sheet section 48 is also passed through a heating chamber to aid in the drying and setting process. The finished new gypsum sheet section 48 is then prepared for storage and transport as commonly done in gypsum board manufacturing. The finished new gypsum sheet section 48 and an adjacent second new gypsum sheet section 48 are folded onto each other about adjacent edges and are taped to each other, or the finished new gypsum sheet section 48 is prepared for storage and shipping by another appropriate method.

In summary, the present invention intends to introduce a commercially viable method and apparatus to apply tapers to all edges on all or some gypsum board (drywall) sheets manufactured. The method primarily provides three additional steps into the present production process. The important steps in the method for the present invention are: impressing a triangular tapering protrusion 71 into the continuous gypsum sheet 9 to form a tapered impression 5; cutting the continuous gypsum sheet 9 into sections, producing new gypsum sheet sections 48 of varying lengths with multiple tapered edges; and enclosing the newly tapered edges, (the first tapered edge 21 and the third tapered edge 23) with a finishing paper when the new gypsum sheet section 48 has completely dried. The preferred embodiment of the present invention is a new drywall sheet measuring 4 feet by 4 feet with all edges tapered. Said sheet will be at least half the size of the smallest full drywall sheet presently being manufactured, which is 4 feet by 8 feet. A smaller 4 foot by 4 foot drywall sheet is easier to transport and install, and the implementation of multiple tapered edges makes finishing the install of the drywall sheet simpler, eliminating “butt” seams.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

What is claimed is:
 1. A gypsum board with multiple tapered edges comprises, a main flat body; a plurality of edges; the main flat body comprises a first paper sheet, a second paper sheet, and a gypsum core; the plurality of edges being positioned on the main flat body; the plurality of edges being perimetrically connected around the main flat body; the plurality of edges comprises a first tapered edge, a second tapered edge, and a third tapered edge; the first tapered edge being oriented perpendicular to the second tapered edge; the first tapered edge and the third tapered edge being oriented parallel to each other; and the first tapered edge and the third tapered edge being positioned opposite each other across the main flat body.
 2. The gypsum board with multiple tapered edges as claimed in claim 1, wherein the main flat body has rectangular geometry.
 3. The gypsum board with multiple tapered edges as claimed in claim 1, wherein the gypsum core is positioned between the first paper sheet and the second paper sheet.
 4. The gypsum board with multiple tapered edges as claimed in claim 1 comprises, the plurality of edges further comprises a fourth tapered edge; the fourth tapered edge being oriented parallel to the second tapered edge; the fourth tapered edge being positioned opposite to the second tapered edge across the main flat body; and the second tapered edge and the fourth tapered edge being positioned adjacent to the first tapered edge and the third tapered edge, wherein the first tapered edge, the second tapered edge, the third tapered edge and the fourth tapered edge form a rectangular perimeter.
 5. A gypsum board with multiple tapered edges comprises, a main flat body; a plurality of edges; the main flat body comprises a first paper sheet, a second paper sheet, and a gypsum core; the plurality of edges being positioned on the main flat body; the plurality of edges being perimetrically connected around the main flat body; the plurality of edges comprises a first tapered edge, a second tapered edge, and a third tapered edge; the first tapered edge being oriented perpendicular to the second tapered edge; the first tapered edge and the third tapered edge being oriented parallel to each other; the first tapered edge and the third tapered edge being positioned opposite each other across the main flat body; the main flat body having flat, rectangular geometry; and the gypsum core being positioned between the first paper sheet and the second paper sheet.
 6. The gypsum board with multiple tapered edges as claimed in claim 5 comprises, the plurality of edges further comprises a fourth tapered edge; the second tapered edge and the fourth tapered edge being oriented parallel to each other; the fourth tapered edge being positioned opposite to the second tapered edge across the main flat body; and the second tapered edge and the fourth tapered edge being positioned adjacent to the first tapered edge and the third tapered edge, wherein the first tapered edge, the second tapered edge, the third tapered edge and the fourth tapered edge form a rectangular perimeter.
 7. A method for manufacturing a gypsum board with multiple tapered edges comprises the steps of, providing a conveyor system; providing a quantity of gypsum slurry; providing an upper paper sheet and a lower paper sheet; providing an upper bracket and a lower bracket, wherein the lower bracket comprises a triangular tapering protrusion; providing a dividing blade; continuously feeding the quantity of gypsum slurry between the upper paper sheet and the lower paper sheet with the conveyor system to form a continuous gypsum sheet; wherein a length of the continuous gypsum sheet is defined by movement along the conveyor system; wherein longitudinal edges of the continuous gypsum sheet are parallel to the movement of the conveyor system; tapering the longitudinal edges of the continuous gypsum sheet, wherein the longitudinal edges of the continuous gypsum sheet become the first tapered edge and the third tapered edge of the gypsum board with multiple tapered edges; waiting for the gypsum slurry to partially dry, wherein the gypsum slurry is allowed to dry to a point where the gypsum slurry is a moldable solid that can be shaped by applying a compressive force; transversely compressing the continuous gypsum sheet at a specified location along the length of the continuous gypsum sheet between the upper bracket and the lower bracket to form a transverse tapered impression in the gypsum slurry adjacent to the lower paper sheet; dividing the continuous gypsum sheet by centrally cutting the transverse tapered impression with the dividing blade to produce a new gypsum sheet section; wherein the new gypsum sheet section comprises transverse tapered edges; wherein the transverse tapered edges are the second tapered edge and the fourth tapered edge of the gypsum board with multiple tapered edges; enclosing the transverse tapered edges with a finishing paper to form a finished new gypsum sheet section; and waiting until the finished new gypsum sheet section is completely dry.
 8. The method for manufacturing a gypsum board with multiple tapered edges as claimed in claim 7 comprises the steps of, raising the lower bracket into the continuous gypsum sheet, wherein the lower bracket is raised through a gap between lower wheels of the conveyor system; piercing the lower paper sheet with the triangular tapering protrusion; stabilizing the continuous gypsum sheet opposite the lower bracket by the upper bracket, wherein the upper bracket allows the force transmitted by the lower bracket to compress the gypsum slurry into the transverse tapered impression; and compressing a portion of the gypsum slurry adjacent to the lower paper sheet into an isosceles triangular shape, wherein equal sides of the isosceles triangle converge in a direction from the lower paper sheet toward the upper paper sheet. 